Cabin Air Filter and Filter Element for a Cabin Air Filter

ABSTRACT

A cabin air filter is provided with a filter element receptacle and a filter element having a fold pack. The filter element is inserted in an insertion direction into the filter element receptacle. The filter element is provided with a sword that extends in the insertion direction away from a face of the filter element. The filter element has lateral strips that close off the fold pack on at least two sides of the fold pack. The sword is preferably inherently stable so that it can transmit compressive forces from the filter element to the receptacle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of internationalapplication No. PCT/EP2013/060112 having an international filing date of15 May 2013 and designating the United States, the InternationalApplication claiming a priority date of 15 May 2012, based on priorfiled German patent application No. 10 2012 009 595.3, the entirecontents of the aforesaid international application and the aforesaidGerman patent application being incorporated herein by reference.

BACKGROUND OF THE INVENTION

The invention concerns an air filter, in particular a cabin air filtere.g. for a motor vehicle, in particular in an air conditioning device,as well as a filter insert for such a filter.

DE 10 2005 048 841 discloses a cabin air filter in which a filterelement receptacle comprises a guide pin that is inserted into a guidepassage in a filter element when the filter element is inserted alongits longitudinal axis into the filter element receptacle. Other cabinair filters are known in which shaped elements on a filter elementreceptacle require complementary shaped elements of the filter elementso that the filter element upon insertion into the filter elementreceptacle can terminate seal-tightly therewith.

DE 102 31 696 A1 discloses a filter insert that has an end cap that isdesigned in one embodiment in a T-shape so that a web in the plane ofthe filter element is projecting away from the filter element.

DE 20 2005 011 078 U1 discloses a filter element that comprises asealing strip that is attached e.g. on three sides about the filterelement.

A disadvantage of such filters is that the filter element must bematched precisely to the corresponding filter, respectively. Forexample, a filter insert for a cabin air filter of DE 10 2005 048 841must have its guide receptacles precisely at the positions of the guidepins. The sealing strip of DE 20 2005 011 078 U1 may compensate minimalunevenness but has e.g. an inherent uniform thickness; the same holdstrue for the web of DE 102 31 696 A1. Solutions would be desirable inwhich a filter element is suitable for various configurations of thefilter element receptacle or is more easily adaptable.

SUMMARY OF THE INVENTION

This object is solved by a cabin air filter comprising a filter elementreceptacle and a filter element comprising a fold pack. The filterelement can be inserted along an insertion direction into the filterelement receptacle or can be displaced therein. The filter elementcomprises a sword which is extending away from a face of the filterelement in the insertion direction or displacement direction.Preferably, the sword is inherently stable such that it can transmitcompressive forces from the filter element onto the filter elementreceptacle which may lead to a sealing action of the filter element inthe filter receptacle.

The filter element may comprise lateral strips that close off the foldpack on at least two sides. Preferably, the lateral strips are made ofnonwoven material.

The filter element may comprise a fold pack that has a plastic materialinjection-molded around it. In this way, a plastic frame for the filterelement is formed.

Preferably, the sword is embodied as a flat plastic part. In thiscontext, it can be embodied e.g. of several plastic materials, e.g. aless elastic first plastic material and a more elastic second plasticmaterial, wherein the second plastic material seals the sword relativeto the filter element receptacle. Such a system can be produced e.g. bya 2-component method.

The sword can also be a part of a plastic part that is connected withthe lateral strips.

The sword can be part of the plastic frame in a fold pack that has aplastic material injection-molded around it.

The sword can also be embodied of filter medium, in particular of atwo-layer or multi-layer filter medium. The multilayer configuration,possibly together with an adhesive, may provide the sword with therequired stability.

The sword can be designed to be slanted relative to the plane of thefold pack. In this way, seals attached e.g. at different heights on thesides of the filter element can be connected at the side facing in theinsertion direction.

Preferably, the sword has a length of more than 2 cm in the direction ofthe insertion or displacement direction.

In various embodiments, the sword can have a shape in the filter elementplane that deviates from the rectangular shape. For example, the swordcan have an asymmetric shape. The sword can be matched to a contour,e.g. an asymmetric and/or non-rectangular contour, of a housing.

The object is solved by a filter element for a cabin air filter with theillustrated features for in particular the sword as well as a method forinstallation of such a filter element in a cabin air filter.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages, features, and details of the invention result fromthe following description in which embodiments of the invention will beexplained in more detail with the aid of the drawings.

FIG. 1A is a top view of a filter element for a cabin air filter havinga sword in longitudinal direction of the filter element, wherein thesword is attached as a plastic part onto the filter element;

FIG. 1B is a partial left side sectional view of the filter element ofFIG. 1A;

FIG. 1C is a perspective view of the sword of FIGS. 1A and 1B;

FIG. 1D is a rear end view of FIG. 1A showing the insertion end of thefilter element;

FIG. 2A is a top view of a filter element for a cabin air filter havinga sword in longitudinal direction of the filter element, wherein thesword is manufactured of the filter medium of the fold pack of thefilter element;

FIG. 2B is a partial left side section view of the filter element ofFIG. 2A;

FIG. 2C is a rear end view of FIG. 2A showing the insertion end of thefilter element;

FIG. 3A is a top view of a filter element for a cabin air filter havinga sword in the longitudinal direction of the filter element, wherein thesword is made of foam material;

FIG. 3B is a left side view of the filter element of FIG. 3A;

FIG. 3C is a rear end view of FIG. 3A showing the insertion end of thefilter element;

FIG. 3D is a perspective view of the filter element of FIG. 3A includingan additional plastic part for sealing;

FIG. 3E is a perspective view of the additional plastic part for sealingof FIG. 3D;

FIG. 4A1 is a top view of an alternative configuration of a filterelement for a cabin air filter that enables a simple adaptation togeometries of a filter element receptacle;

FIG. 4A2 is a partial left side section view of the filter element ofFIG. 4A1;

FIG. 4A3 is a perspective view of the PU foam block of the filterelement of FIGS. 4A1 and 4A2;

FIG. 4B1 is a top view of a second alternative configuration of a filterelement for a cabin air filter that enables a simple adaptation togeometries of a filter element receptacle;

FIG. 4B2 is a partial left side sectional view of the filter element ofFIG. 4B1;

FIG. 4B3 is a rear end view of FIG. 4B1 showing the insertion end of thefilter element;

FIG. 4B4 is a perspective view of the PU foam block of the filterelement of FIGS. 4B1-4B3; and

FIGS. 5A and 5B are schematic side sectional views of alternativeconfigurations of a filter element for a cabin air filter that enable asimple adaptation to geometries of a filter element receptacle.

In the Figures, same components are provided with same referencecharacters.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1A-1D show a filter element 1 for a cabin air filter comprising asword 7 in longitudinal direction of the filter element 1, wherein thesword 7 is attached as a plastic part 10 to the filter element 1. Thefilter element 1 comprises a fold pack 2 which tapers in the insertiondirection of the filter element. One side of the filter element 1 isprovided with a front plate 3 which, in the mounted state, forms theclosure in outward direction and closes off a filter element receptacle.The fold pack comprises a plurality of folds 6 of a filter medium. As afilter medium, paper or nonwoven can be provided; the filter medium maycomprise adsorbent materials, e.g. active carbon. The fold pack 2 isprovided at the end edges with lateral strips 4 which close off thefolds, optionally constitute a termination and a sealing element of thefilter medium, when the latter is containing e.g. active carbon. Thelateral strips 4 can be manufactured e.g. of nonwoven. On the twolateral strips 4 a seal 5 is applied, for example, a foam material stripthat realizes the lateral sealing action of the filter element 1 in thefilter element receptacle.

The sealing action of the rear side of the filter element 1 in theinsertion direction is realized by a sword 7. The sword 7 is part of aplastic part 10 and can be attached with a U-shaped attachment area 8 ofthe plastic part onto the filter element 1. The last fold 6 of the foldpack 2 can be inserted into the U-shaped area 8 and glued thereto. TPE(see FIG. 10) means thermoplastic elastomer; PP means polypropylene. Theplastic part 10 can be connected or glued or fused to the lateral strips4.

In an alternative configuration, a plastic material can also beinjection-molded around the fold pack 2 and preferably secured to thefold pack, replacing the lateral strips. In this way, the lateral stripscan be eliminated and the plastic part 10 may be connected also, e.g.even monolithically formed with the injection molded plastic material ofthe frame. The sword 7 in all variants can be made of an elastic plasticmaterial or a combination of elastic and less elastic plastic materials.In particular, the sword can be produced by the 2-component method oftwo different plastic materials or of one or several thermoplasticelastomers (TPE). With such a sword 7, the filter surface area isreduced; however, in particular in case of a form of the fold pack 2 asshown in FIGS. 1A-1D the reduction is in the area of the fold pack thathas a reduced width and has possibly at the rim a reduced flow-throughaction. For different shapes on the part of the filter elementreceptacle, a filter element 1 for which only the plastic part 10 mustbe changed can be used. The disadvantage of reduced filter surface areais thus counterbalanced by an advantage in regard to manufacture.

FIGS. 2A-2C show a filter element 1 for a cabin air filter comprising asword 7 in the longitudinal direction of the filter element 1, whereinthe sword 7 is manufactured of the filter medium of the fold pack 6 ofthe filter element. Accordingly, in contrast to the variant of FIGS.1A-1D, the sword 7 can be realized from the filter medium itself and anadditional component is not required.

FIGS. 3A-3E show a filter element 1 for a cabin air filter comprising asword 7 in the longitudinal direction of the filter element, wherein thesword is manufactured of foam material. Independent of the material ofthe sword 7, herein the sword 7 not only can be formed in the plane ofthe fold pack 2 but can also extend at a slant thereto. In this way, asealing configuration can be realized, for example, in which the lateralsealing action with the seals 5 extends at different height of the foldpack 2 on the two sides of the filter element. This is particularlyadvantageous when the material of the seals 5 can be used for the sword7, e.g. foam material, such as PU (polyurethane). The filter element 1in FIGS. 3A-3E may comprise an additional plastic part 9 secured theretothat can contribute to a lateral sealing action and may be secured tothe sword or serve as a carrier or support for the sword.

FIGS. 4A1-4A3 and 4B1-4B4 as well as FIGS. 5A and 5B show alternativeconfigurations of a filter element 14 for a cabin air filter thatenables a simple adaptation to geometries of a filter elementreceptacle.

In FIGS. 4A1-4A3, a variant is illustrated in which a foam materialblock with weakened zones enables receiving of non-planar areas of thefilter element receptacle. The foam material block can comprise e.g. aplurality of foam material prisms positioned in the filter element planeor a plurality of recesses or cuts.

FIGS. 4B4 shows a plastic end member that by means of two swords orlips, possibly also of different geometry, enables adaptation to afilter element receptacle. The plastic end member is visible also inFIGS. 4B1-4B3.

FIGS. 5A and 5B show variants for a filter element in which the filtermedium in the insertion or displacement direction is formed such that anadaptation to a filter element receptacle is enabled. For example, thefilter medium can be provided with a fold height that is reducedrelative to a greater area of the filter element so that in this way anadaptation to a filter element receptacle is provided. The area ofreduced fold height not only can terminate, as shown in FIG. 5A, with afold tip plane of the filter element but can also be staggered, e.g.centrally arranged. The filter medium or the filter bellows can beframed in the area of reduced fold height on both sides by lateralstrips. The area of reduced fold height can terminate with an L-shapedangle piece, as shown in FIG. 5A, or a U-shaped profile, as shown inFIG. 5B.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the inventive principles, it will beunderstood that the invention may be embodied otherwise withoutdeparting from such principles.

What is claimed is:
 1. A cabin air filter comprising: a filter elementreceptacle; a filter element comprising a fold pack; wherein the filterelement is configured to be inserted in an insertion direction into thefilter element receptacle; wherein the filter element comprises a swordthat extends in the insertion direction away from a face of the filterelement.
 2. The cabin air filter according to claim 1, wherein thefilter element comprises lateral strips that close off the fold pack onat least two sides of the fold pack.
 3. The cabin air filter accordingto claim 2, wherein the filter element comprises a plastic part that isconnected with the lateral strips, wherein the sword is a part of saidplastic part.
 4. The cabin air filter according to claim 1, wherein thefold pack is surrounded by a plastic frame of plastic materialinjection-molded around the fold pack.
 5. The cabin air filter accordingto claim 4, wherein the sword is a part of said plastic frame.
 6. Thecabin air filter according to claim 1, wherein the sword is a flatplastic part.
 7. The cabin air filter according to claim 1, wherein thesword is formed of a filter medium of the fold pack.
 8. The cabin airfilter according to claim 7, wherein the filter medium is a two-layerfilter medium or a multi-layer filter medium.
 9. The cabin air filteraccording to claim 1, wherein the sword is slanted relative to a planeof the fold pack.
 10. The cabin air filter according to claim 1, whereinthe sword has a non-rectangular shape or an asymmetric shape.
 11. Thecabin air filter according to claim 10, wherein the sword is matched toa contour of the filter element receptacle.
 12. The cabin air filteraccording to claim 1, wherein the filter element receptacle comprisesguiding or disturbing structures extending into an interior of thefilter element receptacle.
 13. The cabin air filter according to claim12, wherein the guiding or disturbing structures are pins.
 14. A filterelement for a cabin air filter according to claim
 1. 15. A method forinstalling a filter element in a filter element receptacle of a cabinair filter according to claim 1, the method comprising: providing thefilter element with a sword that is inherently stable; inserting thefilter element into the filter element receptacle; transmitting with thesword compressive forces from the filter element onto the filter elementreceptacle to seal the filter element in the filter element receptacle.